Re: [PATCH 8/9] git_config_set: use do_config_from_file() directly

From: Jeff King <peff@peff.net>
Date: Mar 29, 2018, 21:38 UTC
Message-ID: <20180329213823.GH2939@sigill.intra.peff.net>
In-Reply-To: <e3032300946eb5962878341f7796f5872c4d138d.1522336130.git.johannes.schindelin@gmx.de>

On Thu, Mar 29, 2018 at 05:19:04PM +0200, Johannes Schindelin wrote:

Show 12 quoted lines

> Technically, it is the git_config_set_multivar_in_file_gently()
> function that we modify here (but the oneline would get too long if we
> were that precise).
> 
> This change prepares the git_config_set machinery to allow reusing empty
> sections, by using the file-local function do_config_from_file()
> directly (whose signature can then be changed without any effect outside
> of config.c).
> 
> An incidental benefit is that we avoid a level of indirection, and we
> also avoid calling flockfile()/funlockfile() when we already know that
> we are not operating on stdin/stdout here.

I'm not sure I understand that last paragraph. What does flockfile() have to do with stdin/stdout?

The point of those calls is that we're locking the FILE handle, so that it's safe for the lower-level config code to run getc_unlocked(), which is faster.

So without those, we're calling getc_unlocked() without holding the lock. I think it probably works in practice because we know that we're single-threaded, but it seems a bit sketchy.

-Peff